Suzuki Splash interior light not coming on when open doors

You checked the light switch is in correct position ? If so and you have external courtesy light switches on door / body , would think they must be faulty. A lot of switches nowadays are micro switches built into the lock assembly and often stick or fail

Thanks for responding. I took the rubber housing off all 4 door switches and sprayed. None of them seem sticky in their mechanism. The boot light also doesn't come on. Is there any chance they could be connected to changing the clock with daylight saving?! It seems strange to me that all 4 door switches should stop working at once unless they are all off the driver's side door.

One thing. I somehow at some point lost the boot light... came out of its housing and may have been wrenched off but I have since replaced. Would this wrenching have an effect on the doors?
Thanks so much.